Heat sink

ABSTRACT

The heat sink includes a tube and a plurality of fins. The tube has slots and grooves. Each the groove is located between two adjacent ones of the grooves. The fins are separately fastened to the slots. Each the fin has two walls separately fastened to two of the grooves and a bridge connected between the two walls. An airflow passage is formed among the bridge and the walls.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates to heat sinks, particularly to radial heat sinks.

2. Related Art

Heat sinks are an essential element for many kinds of electric devices,particularly for LED lamps which are progressively popular around theworld. High temperature of heat sinks easily cause scalds to users,especially to children.

Korean patent No. 10-0994603 (hereinafter “KR '603”) discloses a radialheat sink. As shown in FIG. 7 of KR '603, all fins are formed by foldinga single sheet of metal. In other words, all fins are continuous. Such astructure requires a forming process and a folding process with veryhigh accuracy. An allowable error is very narrow. This will increasemanufacturing costs.

SUMMARY OF THE INVENTION

An object of the invention is to provide a heat sink which uses separatefins and a tube to combine together so as to reduce manufacturingaccuracy and costs.

To achieve the above object, the heat sink of the invention includes atube and a plurality of fins. The tube has slots and grooves. Each thegroove is located between two adjacent ones of the grooves. The fins areseparately fastened to the slots. Each the fin has two walls separatelyfastened to two of the grooves and a bridge connected between the twowalls. An airflow passage is formed among the bridge and the walls.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the fin of the invention;

FIG. 2 is an exploded view of the invention;

FIG. 3 is a top plan view of the invention;

FIG. 4 shows the invention is combined with a heat source;

FIG. 5 is a cross-sectional view of FIG. 4;

FIG. 6 is a perspective view of the fin of another embodiment;

FIG. 7 is a perspective view of the fin of still another embodiment; and

FIG. 8 is a perspective view of the fin of yet another embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Please refer to FIGS. 1-3. The heat sink of the invention includes atube 11 and a plurality of fins 20. The outside of the tube 11 is formedwith slots 12 for being fastened by the fins 20 and grooves 13. Each ofthe grooves 13 is located between two adjacent ones of the slots 12 forbeing inserted by a mold (not shown). A hollow 14 of the tube 11 is usedfor receiving a heat source. Each of the fins 20 has two walls 21, 22and a bridge 23 therebetween. The bridge can be planar or non-planarsuch as an arcked surface or a bent surface. Internal sides of the walls21, 22 are separately inserted into the slots 12 so that the fins 20 areradially arranged around the tube 11. When the grooves 13 are pressed bythe mold, the grooves 13 will be deformed to make the slots 12 tightlynip the fins 20.

Each of the walls 21, 22 of the fins 20 is disposed with three throughholes 24 and the bridge 23 is disposed with five through holes 25. Anairflow passage 26 is formed by the walls 21, 22 and the bridge 23. Thiscan improve efficiency of convection.

Please refer to FIGS. 1 and 4. The tops of the walls 21, 22 areseparately formed with two engagement portions 211, 221 for connecting abase 30 and the bottoms of the walls 21, 22 are separately formed withtwo recesses 212, 222 for connecting a frame 40 to form an LED lamp 1.Further, the heat source 15 may be cloaked by a cover 50. The cover 50is made of metal or plastic and fastened in the frame 40.

Please refer to FIGS. 6 and 7, which show another embodiment of theinvention. In this embodiment, the bridge 23 a is provided with an openarea 23 b to improve effect of convection.

FIG. 8 shows still another embodiment of the invention. In thisembodiment, the fins 20 are four in number.

It will be appreciated by persons skilled in the art that the aboveembodiments have been described by way of example only and not in anylimitative sense, and that various alterations and modifications arepossible without departure from the scope of the invention as defined bythe appended claims.

1. A heat sink comprising: a tube, having slots and grooves, whereineach the groove is located between two adjacent ones of the grooves; anda plurality of fins, separately fastened to the slots, wherein each thefin has two walls separately fastened to two of the grooves and a bridgeconnected between the two walls, and an airflow passage is formed amongthe bridge and the walls.
 2. The heat sink of claim 1, furthercomprising a bridge disposed between the two walls.
 3. The heat sink ofclaim 2, wherein the bridge has at least one through hole.
 4. The heatsink of claim 1, wherein each of the walls is provided with at least onethrough hole.
 5. The heat sink of claim 1, wherein a top of each the finhas an engagement portion.
 6. The heat sink of claim 1, wherein a bottomof each the fin has a recess.
 7. The heat sink of claim 1, wherein thebridge has an open area.
 8. The heat sink of claim 1, wherein the bridgeis planar.